Improvement in screw-cutting machines



H. 0. REED. Scfew-Cutting Machines.

Patented August5,1873.

TATES PATENT OFFICE.

IMPRVEMENT IN SCREW-CUTTING MACHINES.

Specification forming part of Letters Patent No. 141,460, dated August 5, 1873; application flled May 16, 1873.

T0 all wwm it may concern:

Be it known that I, HENRY O. REED, of Boston, in the connty of Suftolk and State of MassachnSetts, have invented an Improved Machine for Cntting Threads and Tapping Nnts, of which the following is a specification:

In the drawings, Figure 1 is a plan; Fig. 2, an elevation; Fig. 3, a section on the dotted line of Fig. 2. Fig. 4 shows one of the devices detached from the machine.

My machine consists of a bed-piece, A, on which is secured a head, B, as shown in the drawings. On this head B are two nprights snpporting the boxes b b of the shaft 0. This shait is hollow, and is provided with the holder D, at its inner end. At its onter end it is formed to enter the sleeve on the hui) E, to which it is secnrely held (after it has been placed in the boxes Z) 1)) by means of apin passing through it and the sleeve. In cutting threads the dies are secured to the plate D, the axis of the die coinciding With the axis of the hollon shaft 0. In the drawings I have shown a die which consists of two casting's, F and G, each of which is provided With a notch capable of receivin g and holding a small steel piece upon which the thread-cntters are formed. These castings are arranged each npon its setscrew, Which project from the face of the dieplate D, and are held in place, when properly adjnsted, by these set-screws, and by pins et a, Figs. 1 and 2, which pass through the plate D and into the castings. The small steel pieces are so formed that they Will be secnrely held in the notch, which they fit accnrately. 1 prefer to make these castings disk-shaped, and to form a series of notches in each, and to fit a steel piece in each notch, so that by merely starting the set-screws and taking ont the pins, the disks can be tnrned and readjnsted hg, tightening the set-screws and replacing the pins, and a die of a difierent size be thereby hronght into position. When the threadcnttcrs on the small steel pieces are worn or injnred, the casting can be readily taken off, and a 110W piece inserted. This combination of parts constitutes an important featnre of my invention.

The rod to be threaded is held between the jaws H H, which are monnted in ways on the head I, and are actuated by the right-and-left screw J. This head I is monnted in the bedpiece A, so that it is free to be moved to and from the die-plate D. When the rod is properlyyclarnped between the jaws H H the head I is moved toward the dia-plate, and the end of the rod pressed into the die,by means of the lever K. This lever K is fulcrumed upon the head 1, and has upon its end a sliding spring-pawl, L, which cakes in a rack upon the bed-piece. The pin which forms the fularum of the lever K passes through a slot in the pawl L, and a stem from this pawl L lies within the coils of a spiral spring which lies in a chamber in the lever K, so that the paWl can move endwise on the lever K against the spiral spring. This device constitntes also one featnre of my invention.

When nuts are to be tapped the die-plate is removed from its holder D, and a chuck for holding the tap is substitnted, in the wellknown manner, the nutblank being held by means of the jaws H H, as nsual.

What I claim as my invention is 1. The castings F and G, in combination with the snall steel pieces, the set-screws, the pins a a, and the die-plate D, as above de scribed.

2. The lever K having for its fnlcrnm the slidin g springpawl L, bearing in a rack in the bed A, in combination with the head I and jaws H H mounted in ways in the bed A, and with the clic-plate D bearing a cntting-tool, so that the screw or nul: held in the jaws may be forced against the cutting-tool by the lever, all snbstantially as described.

Signed this 14th day of May, 1873.

HENRY O. REED.

Witnesses:

J. E. KNOX, J. E. MAYNADIER. 

